// Copyright [2020] <unknown>
#include <bits/stdc++.h>
using namespace std;
// #define ONLINE_JUDGE
#ifndef ONLINE_JUDGE
#define dbg(x...)                             \
    {                                         \
        cerr << "\033[32;1m" << #x << " -> "; \
        err(x);                               \
    }
void err() { cerr << "\033[39;0m" << endl; }
template <typename T, typename... A>
void err(T a, A... x) {
    cerr << a << ' ';
    err(x...);
}
#else
#define dbg(...)
#endif

#define sz(x) ((int)x.size())

typedef long long LL;

int t, n;

const int N = 1e5 + 50;

int a[N];
int main(int argc, char const *argv[]) {
    // code
    scanf("%d", &t);
    for (int kk = 0; kk < t; ++kk) {
        scanf("%d", &n);
        for (int i = 0; i < n; ++i)
            scanf("%d", &a[i]);
        bool fd = false;
        for (int i = 0; i < n; ++i) {
            if (a[i] % 2 == 0) {
                printf("1\n%d\n", i + 1);
                fd = true;
                break;
            }
        }
        if (fd) continue;
        if (n >= 2) {
            printf("2\n1 2\n");
        } else
            puts("-1");
    }
    return 0;
}
